(1) Field of the Invention
The present invention relates to an electrophotographic copying machine for copying an original document placed in a predetermined position on a document supporting glass plate to a selected position such as a central position of copying paper.
(2) Description of the Prior Art
The electrophotographic copying machine generally takes copies of an original document placed on the document supporting glass plate with an end of the document extending along an end of the glass plate, whereby the copies are tranferred to copying paper having an end thereof in register with the end of the document. In other words, a position adjusting control is effected through timing rollers for feeding the copying paper such that the ends of the document and the copying paper coincide with each other. This control has no problem where both the document and copying paper are in a regular size. However, where either the document or the copying paper is outside regular sizes as, for example, when copying a message or a title to a central position of a wrapping paper or a cover sheet and the original document is smaller than the copying paper, there arises the problem of a copied image being positioned too close to the forward end of copying paper.
In order to solve this problem, a proposal has been made in the Japanese laid open patent application (Kokai) under No. 59-216158. In the copying machine disclosed therein, an original document is set by an automatic document feeder to such a position on the document supporting glass plate that its image is copied to the center of copying paper and, thereafter, copies are taken under control effected through the timing rollers as noted above. In this prior copying machine, however, the timing rollers are controlled to feed the copying paper so that its forward end comes into register with the forward end of the document set to an end position of the document supporting glass plate. The document must, therefore, be set to different positions depending on the sizes of the copying paper and on the copying magnifications. This entails complications in the control for the automatic document feeder and, when the automatic document feeder is not used, presents difficulties in setting the original document to a correct position. It also has the disadvantages of consuming time for selecting the document position and causing incorrect setting of the original document. Furthermore, where the copying paper has a great length or in the case of a great magnification, the document setting position must be outside the document supporting glass plate, which makes a copying operation impossible.